Crate aleph_bft

Implements the Aleph BFT Consensus protocol as a “finality gadget”. The [Member] struct requires access to a network layer, a cryptographic primitive, and a data provider that gives appropriate access to the set of available data that we need to make consensus on.

Structs

• Config
  Main configuration of the consensus. We refer to the documentation Section 3.4 for a discussion of some of these parameters and their significance.
• DelayConfig
  Configuration of several parameters related to delaying various tasks.
• IncompleteMultisignatureError
  Error resulting from multisignature being incomplete.
• Indexed
  A pair consistsing of signable data and a NodeIndex.
• LocalIO
• Multisigned
  Signable data together with a complete multisignature.
• NetworkData
  NetworkData is the opaque format for all data that a committee member needs to send to other nodes.
• NodeCount
  Node count. Right now it doubles as node weight in many places in the code, in the future we might need a new type for that.
• NodeIndex
  The index of a node
• NodeMap
  A container keeping items indexed by NodeIndex.
• NodeSubset
• SignatureError
  Error type returned when a verification of a signature fails.
• Signed
  A correctly signed object of type T.
• Terminator
  Struct that holds connections to offspring and parent components/tasks and enables a clean/synchronized shutdown
• UncheckedSigned
  A pair consisting of an instance of the Signable trait and an (arbitrary) signature.

Enums

• PartiallyMultisigned
  Signable data together with a valid partial multisignature.
• Recipient
  A recipient of a message, either a specific node or everyone.

Traits

• Data
  Data type that we want to order.
• DataProvider
  The source of data items that consensus should order.
• FinalizationHandler
  The source of finalization of the units that consensus produces.
• Hasher
  A hasher, used for creating identifiers for blocks or units.
• Index
  Indicates that an implementor has been assigned some index.
• Keychain
  Abstraction of the signing data and verifying signatures.
• MultiKeychain
  Extends Keychain with multisigning functionalities.
• Network
  Network represents an interface for sending and receiving NetworkData.
• PartialMultisignature
  A type to which signatures can be aggregated.
• Signable
  Data which can be signed.
• Signature
  The type used as a signature.
• SpawnHandle
  An abstraction for an execution engine for Rust’s asynchronous tasks.

Functions

• create_config
  Creates a Config which wraps the passed arguments. time_to_reach_max_round is a lower bound on the time needed to reach the maximum round expected by the user and is only used for verification.
• default_config
  Creates a Config, allowing the user to omit specifying the delay_config in which case it will be set to default, suggested by the creators of this package. time_to_reach_max_round is a lower bound on the time needed to reach the maximum round expected by the user and is only used for verification.
• default_delay_config
  Creates a DelayConfig with default parameters, suggested by the creators of this package.
• exponential_slowdown
• handle_task_termination
• run_session
  Starts the consensus algorithm as an async task. It stops establishing consensus for new data items after reaching the threshold specified in Config::max_round or upon receiving a stop signal from exit. For a detailed description of the consensus implemented by run_session see docs for devs or the original paper.

Type Aliases

• Round
  An asynchronous round of the protocol.
• SessionId
  The number of a session for which the consensus is run.
• SignatureSet
  A set of signatures of a subset of nodes serving as a (partial) multisignature
• TaskHandle
  A handle for waiting the task’s completion.